Chair and ancillary apparatus with medical diagnostic features in a remote health monitoring system

ABSTRACT

A medical examination chair includes a group of sensors including electrodes in finger-tip sensors, various other types of sensors incorporated in straps for the patient in the chair and load cells supporting the chair, all of which provide data which is partially processed in the electronics mounted in the chair and then transmitted to central station for patient diagnosis.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This is a utility application based upon and incorporating byreference the following three provisional applications: Serial No.60/232,708, filed Sep. 15, 2000, Serial No. 60/205,369 filed May 18,2000, and Serial No. 60/205,144 filed May 18, 2000, upon which we claimpriority.

BACKGROUND OF THE INVENTION

[0002] In a principal aspect, the present invention relates to a chairand ancillary apparatus incorporated with the chair for use in theconduct of medical diagnostic tests in a diagnostic system wherein thesubject may be remotely located.

[0003] U.S. Pat. No. 5,544,649, incorporated herewith by reference,discloses various techniques for interactive patient monitoring from acentral station, (e.g., a clinic) of patients located at a remote site,(e.g., their home). The diagnostic techniques disclosed in U.S. Pat. No.5,544,649 rely, at least in part, upon utilization of apparatus, such asa diagnostic chair incorporating various sensor apparatus to facilitatethe conduct of diagnostic measurements. U.S. Pat. No. 5,544,649discloses a chair which includes sensors for measuring patienttemperature, blood pressure and the like, and for transmitting such datavia alternative transmission means to a central station for analysis anddiagnosis.

[0004] The diagnostic session involving a patient in a remote locationchair may be interactive. That is, the health care professional at thecentral station and the patient at the remote site are in real time,two-way audio and video communication and diagnostic data sensed at theremote location is simultaneously provided in real time to the centralstation. Such communication enhances the validity and the scope of thediagnostic tests being conducted.

[0005] The diagnostic information is analyzed by personnel at thecentral station. This provides a convenient and low cost manner in whichto monitor patient condition without requiring the patient to physicallytravel to a diagnostic clinic or hospital. This technique and theassociated apparatus also enable the health practitioner to direct thepatient through test protocols and to diversify or revise the testprotocols as necessary during the interactive session.

[0006] The use of apparatus of this type disclosed, and, in particular,a chair and various other ancillary equipment have become the topic ofcontinued research and development in order to provide apparatus whichsenses the diagnostic parameters necessary to provide immediate andappropriate patient health care or monitoring in an inexpensive, yethighly reliable manner. Such continued research and development has ledto the discovery of the apparatus disclosed hereinafter and alsoprovides for the combination of such apparatus in an interactivediagnostic system.

SUMMARY OF THE INVENTION

[0007] Briefly, the present invention relates to the construction anddesign of a chair or other support platform device used for subjectmonitoring and medical examination and to the combination of such adevice with a system for remote monitoring from a central station.

[0008] The device in the form of a chair or platform incorporatesnumerous apparatus for the acquisition of physiological and otherdiagnostic parameters from a subject who is sitting in or lying on thedevice. In a preferred embodiment, a chair is utilized which acceptscommands for the acquisition and analysis of diagnostic data and sendsthe results, either processed on site and/or as raw data, by wirelesscommunication to a relay system located at the site. The relay systemthen transfers data received from instrumentation incorporated in thechair to a central system by means of a wide bandwidth public channel(e.g., wireless network, telephone system, cable modem or other publicutility). Communication and sensor control is interactive. That is, thetransmissions are two-way transmissions. Additionally, two othercommunication channels are simultaneously operative, i.e., audio andvideo are interactive. Simultaneous, two-way transmission on threechannels results in the capacity to diagnose and, to a limited extent,treat a patient at a remote site interactively. The channels may also beintegrated for example by modulation or packing of a single channelsignal.

[0009] By way of example and not limitation, the following medicalinformation and testing, protocols are enabled by the chair or platformdesign: (1) finger-tip ECG, (2) “safety-belt” diagnostic ECG, (3)non-invasive blood pressure, (4) weight, (5) balance, (6) respirationrate, (7) saturated pulse oximetry (Sp02), (8) blood glucose analysis,(9) lung sounds, (10) expiratory flow (respiration exhale and/or inhaleflow rates), (11) skin resistance, and (12) hand grip strength. All ofthe instrumentation required for the various measurements recited are anintegral part of the chair. No special knowledge, expertise, or physicaldexterity is required on the part of the patient or subject toparticipate in the test procedures since all of the instruments are anintegral part of the chair or device. The chair also provides anergonomically safe support for the patient, an aesthetically pleasantappearance and includes storage for the sensors and instruments not inuse.

[0010] Exemplary of the diagnostic capabilities of the system and chairis measurement of hand grip strength of a patient. That is, a hand gripinstrument can detect whether the patient suffers from tremors whengripping an object and thus can be relied upon as a diagnostic tool toevaluate the health of a patient. Apparatus which provide information ofthis general nature also allows assessment of motor activity which isassociated with neurological features or capacity of a patient as wellas strength which is associated with the muscle characteristics of apatient. Such monitoring is capable of projecting the likelihood orimpact of stroke, for example, and other patient abnormalities.

[0011] Thus, a hand grip monitoring device which, in one embodiment,includes a bladder in the form of an elongated ellipsoid may beprovided. A source of pressurized fluid is provided to the bladder witha check valve connected to the bladder filled with a predeterminedvolume of fluid (e.g., gas or liquid). A sensor is connected to thebladder for monitoring the fluid pressure in the bladder and providing afirst signal which represents the absolute pressure therein and a secondsignal representative of the change in pressure over time. A recorder isprovided for recording the first and second signals. Data associatedwith the first and second signals is analyzed, the first signal beingrepresentative of the total energy associated with patient grip and thesecond signal associated with tremors or a change in pressure with time.As indicated heretofore, tremors may be indicative of neurologicalstatus, neuromuscular pathology or stroke. The system may includehistorical recordings of like signals or a library of data to comparewith the measurement or sensed signals in order to determine the changein patient health with time. Alarms may be provided to alert the medicaltechnician at the central station of deviation beyond the generalpatient specific norm.

[0012] Another example involves load cells mounted on the support legsof the chair or device. The cells detect shifts in weight which, inturn, can be relied upon to diagnose balance and other physiologicalcharacteristics of a patient.

[0013] The chair and its associated diagnostic sensors may be utilizedin combination with a remote monitoring system or infrastructure whichoperates from a central station by communication techniques withmultiple, remote sites.

[0014] It is an object of the invention to provide a diagnostic chair ordevice and other ancillary apparatus used in combination with the chairto provide sensors that reliable interact with a patient for themeasurement of respiration rate, pulmonary condition, heart condition,muscle strength, blood pressure, and other physiological parameters.

[0015] Yet a further object of the invention is to provide a highlyreliable, yet inexpensive diagnostic apparatus comprised of a chair orfurniture which may be utilized at a remote location yet easilytransported from one location to another and easily interfaced withsensor transmission equipment and with a remote diagnostic system of thetype generally depicted in U.S. Pat. No. 5,544,649.

[0016] Another object of the invention is to provide a chair or platformwhich maybe utilized to obtain diagnostic data from subjects located ata remote site for transmission to and recordal at a central station inorder to obtain an historic record of the subject indicative of thewellness or deterioration in wellness of the subject or the status ofrecovery of the subject.

[0017] These and other objects, advantages and features of the inventionwill be set forth in the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWING

[0018] In the detailed description which follows, reference will be madeto the drawing comprised of the following figures:

[0019]FIG. 1 is a side elevation of an embodiment of a chair withsensing apparatus;

[0020]FIG. 1a is an exploded sectional view of a portion of the chairdepicted in FIG. 1;

[0021]FIG. 2 is a front elevation of the chair and ancillary apparatusof FIG. 1;

[0022]FIG. 3 is a schematic view of a hand grip sensor utilized incombination with the chair of the invention and with the systemincorporating the chair;

[0023]FIG. 4 is a diagrammatic view of the diagnostic chair incorporatedin a remote monitoring system;

[0024]FIG. 5 is a block diagram of the signal processing protocol forthe load cells associated with measurement of weight, balance,respiration rate and other physical characteristics of a subject;

[0025]FIG. 6 is a series of graphs depicting the readings from loadcells on a time scale and further depicting readings which represent thesum of various combinations of signals

[0026]FIG. 7 is a series of graphs similar to FIG. 6 representing adistinct physiological pattern;

[0027]FIG. 8 is another series of graphs similar to FIG. 6 representinga further distinct physiological pattern; and

[0028]FIG. 9 is another series of graphs similar to FIG. 6 representinga further distinct physiological pattern or event.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0029] The apparatus of the invention comprises the combination of achair or equivalent subject support platform device such as a bed,gurney or the like with various data, audio and visual transmissioncomponents. Thus, the chair depicted in FIGS. 1 and 2, involves datasensing, collection and transmission, as well as control of sensors inthe chair through the data transmission links or channels. The chairtypically comprises an element of an overall system and hasself-contained sensing and control elements. FIG. 4 illustrates thechair and home unit components of such a system and the invention isdescribed in the embodiment of a chair though other platform devices maybe substituted such as a bed.

[0030] Referring to the figures, an exemplary chair includes thefollowing elements: a seat 14, a back support 16 and an optionalmoveable, cantilever leg support 18. The chair is mounted on four,spaced legs 20 or the equivalent four mounting pads on the bottom of achair base. Each leg 20 or mounting pad is supported on a separate loadcell 22. A stable platform 23 supports the four load cells 22. The loadcells 22 on fixed support platform 23 are used to measure or indicateweight, balance, and weight distribution at any given time and as afunction of time as described in more detail below. The load cells 22preferably are positioned on the corners of a rectangle.

[0031] Back support 16 includes an array of straps 24, 26, 28 and anon-invasive blood pressure cuff strap 33. Strap 26 is an electronicstethoscope strap 26 used for assessment of heart and lung sounds andincludes a respirometer used for measuring respiration data. A “safetybelt” like strap 28 is used for diagnostic ECG (electrocardiogram). The“safety belt” like strap 28 is similar to the design of a safety beltused in an automobile with attached electrodes 29 to permit secureplacement of the electrodes 29 in the appropriate position on a humansubject for obtaining a diagnostic single, multiple or full 12 lead ECGmeasurement. Ancillary electrodes 29 may be provided on the other straps24, 26.

[0032] Moveable, cantilever leg support 18 facilitates raising the legsof a patient from resting on the floor when measuring patient weight byload cells 22. A strain gage 19 in leg support 18 also allowsmeasurement of leg muscle strength. That is, a patient may attempt tolower the support 18 by engagement with their legs. The force impartedon support 18 by such activity may be sensed by a strain gage 19 tothereby provide a measurement of leg strength, muscle condition andmuscle coordination.

[0033] Arm rests or supports 30 include “finger-tip” electrodes 32, 34used for measuring a single lead ECG lead-I and skin resistance. Ahand-grip 36 is used to measure hand muscular strength and control. Askin sensor 38 is used to measure blood glucose measurements. Aninfra-red emitter and sensor 40 is used to measure SpO2. An infra-red(IR) transmitter and receiver 42 is used for wireless communication to atransmission device 44 located at the patient or remote site.Communication device 44 is then linked to a central station, forexample, by a wireless transmission, switched network cable line,telecommunication line or the like. An electronics enclosure 50 isattached underneath the seat 14 and contains the analog to digitalconversion and microprocessor electronics for the operation of thesensor instruments in the chair.

[0034] The chair is designed so that the entire weight of the personsitting in the chair is transferred solely to the load cells 22. Thus,rectangular platform or frame 23 holds four load cells 22 arranged atthe comers of the rectangular platform 23 supporting the chair. Theframe 23 provides a means for physically locating the load cells 22 forsupporting the chair. The frame 23 allows the load cells 22 to be fixedin each of the four corners of the rectangle or in any other desiredgeometric pattern associated with the legs 20 or chair support and thediagnostic protocol. Electronics which provide a common referencevoltage to all load cells 22; differential amplifiers which amplify thetemporal changes due to the weight shift on each load cell 22; bandpassfilter for respiratory monitoring; low pass filter for human balancemonitoring and a microprocessor with a multi-channel analog to digitalconverter are all housed in the enclosure 50. Software which controlsdata collection and signal processing is also incorporated in thehardware in the enclosure 50. Though the four load cells 22 are in arectangular array, additional load cells in other arrays may be utilizedto measure weight distribution as it varies with time over the surfaceof the seat 14 to thereby permit diagnostic measurements of the typediscussed hereinafter. Each of the cells 22 provide a separate,recordable signal to the processing equipment described for ultimatetransmission to a central station.

[0035] Respiration Rate Measurement

[0036] As previously described, a recliner chair is preferably used inorder that support 18 will lift the feet of the patient from the floor.This is done so that all of the body weight of the patient is supportedsolely by the chair and the weight is directed in some pattern ofdistribution to each of the four sensors or load cells 22 under thechair seat 14 during measurement of respiration and other indices ofpatient health. That is, as a patient breathes, there is a small shiftof weight from the back to the front of the chair or vice versa. Thisweight shift is transferred to the appropriate front and back load cells22 in response to the shifting of patient weight due to respiration. Theload cells 22 are thus arranged such that they can detect small changesin load due to patient respiratory induced weight shift. In other words,the load cells 22 are arranged so that they can detect load changes inboth the X and Y directions, i.e., side to side and front to back ofseat 14. As schematically depicted in FIG. 5, a high pass filter may beused to remove the DC component of the weight signal allowing only theAC changes in the signal to be passed. Since the AC changes are verysmall compared with the DC component, AC coupling allows the signal tobe highly amplified. The signal to noise response of the system isimproved by the quadrature nature of the signals. The quadrature natureof the signals arises from the fact that any increase in weight in onedirection in the X-Y plane is compensated by an equal decrease in weightin the opposing direction in the X-Y plane. Noise and non-body movementartifacts thus can be removed from the signal. The front to back andside to side signal change of a sitting or recumbent subject representsrespiration rate and many other physical parameters. In other words, byappropriately positioning load cells 22 and processing the AC componentassociated with changes in weight distribution, the system enables aphysician or diagnostician located at a remote site to monitorrespiration rate of the patient in real time responsive, for example, toinstructed as well as natural breathing patterns. For example, thepatient may have exercised before sitting in the diagnostic chairthereby enabling the diagnostician the opportunity to evaluaterespiration rate following activity as well as at rest. Many variablepatterns of patient activity are possible, all of which may be remotelymonitored using the described system.

[0037] Weight

[0038] The lower portion of the chair acts as a scale that allowsmeasurement of the gross weight of the patient sitting in the seat 14 ofthe chair. To measure total weight, the patient must raise his or herfeet from the floor allowing all of the body weight to fall on the seat14 of the chair. The DC component of the load cells signal is indicativeof weight. Note, the chair may not include the cantilever leg support 18in which event the patient must lift his or her legs from the floor toprovide a true DC weight signal by the load cells 22. Also if theplatform is a bed on gurney, then positioning of cells 22 will bedependent on the size of the platform and the platform will normally besupportive of leg or limb weight.

[0039] Balance

[0040] Each individual who sits down in the chair or gets up from thechair produces a characteristic response signature of time dependentweight distribution on each of the four load cells 22. The signature isused for historical reference to determine if changes in this signaturemay indicate physiological or pathological trauma as suggested, forexample, by a change in patient ability to balance and in the responsetime to the command to change position (e.g., to rise from the chair)following instructions.

[0041] The monitoring of balance is accomplished by recording, forexample, the transient response on the load cells 22 as a patient risesfrom the chair. The transient response provides a characteristic picturesignature of the shifts of body weight as a function of time when thepatient rises. For example, the weight is initially transferred from theback to the front of the chair and then later to the arms 30 whichprovide support for the person rising from the chair. Information fromthe four load cells 22 over time provides a characteristic picturesignature of temporal balance changes as one rises from the chair. Anexample of data provided for diagnostic analysis includes measurement ofthe movement of the center of mass of a patient over seat 14 in the Xand Y directions as a function of time. Unlike respiration, the weightsignals relating to changes in balance and gross weight are largesignals containing the DC element. The system is designed so that thecharacteristic frequency of the load cells 22 is well above the upperfrequency response required from the system.

[0042] Periodic monitoring of a person rising from the chair producesdata pattern signatures. These patterns are stored and statisticallycompared to new data using multidimensional statistical analysis. Whenthe new data pattern signature is significantly different than thestored data pattern, an alarm (not shown) may be activated indicatingthe need for further diagnostic investigation. That alarm may be in thechair, but more appropriately is maintained at the diagnostic center.

[0043] In summary, the load cells 22 generate a myriad of data,including weight or load change as a function of time for each cell 22as well as gross load for each cell 22 as a function of time.Preferably, this data is collected in its most basic form as analogsignals by sensors 22. The signals are then typically converted todigital form by the software and hardware in the chair and transmittedby a wireless transmitter 42 to a receiver 44 at the remote site. Therereceiver 44 may store the data, compress the data and otherwisepreliminarily process the data and subsequently forward the data via apreferred network, for example, to the central station. The datatransmission may be interspersed with data or control signals to thetransmitter 44. The data may thus be downloaded periodically orcontinually and may be processed, in part before transmission ortransmitted in full.

[0044] The load cell 22 signals may be assigned to a single channel fortransmission to the central station separate from the other diagnosticsignals so that the interrelationship of the various diagnosticprotocols may be observed. For example, weight shift data and grossweight data may interrelate with heart rate data to provide diagnosticinsight. Consequently, assigning weight or load cell information to onedata channel and heart rate and condition to another data channel may beoptionally desired and programmed. Other diagnostic information may alsobe simultaneously recorded or sensed and then correlated with heart,weight distribution data, etc. Of course simultaneous audio and videointeraction may also occur to facilitate the diagnostic activity.

[0045]FIGS. 6 through 9 are graphical results derived from load cellmeasurements of the direct current (weight parameter) of the load cells22 in an experiment conducted to evaluate the diagnostic capacity of thedevice. The load cells were placed in a rectangular array with left andright back sensors or load cells 22 attached to the back legs or backedge of the chair and left and right sensors or load cells 22 attachedto with the left and right front legs or front edge of the chair. Eachfigure depicts ten graphs which are the result of the processing of thesignals from the four load cells 22. The first four graphs in the upperportion of each figure comprise or specify the absolute weights sensedby each of the sensors 22 taken during 2 second intervals. The next fourgraphs show differences between the pairs of adjacent sensors asindicated on the figure. The final two graphs show the summeddifferences of the back, the front, and of the left to right sensors,and are indicated as delta right to left and delta back to front.

[0046] Referring first to FIG. 6 there is depicted the results withrespect to a person in good general health without handicap arising froma chair in a very normal fashion. The weight of a person arising fromthe chair is initially shifted from the back (as sensed by the changedetected by the back sensors) to the front of the chair (as detected bythe front sensors) causing the rise in signal and thus the rise inweight detected in the front sensors and a corresponding decrease in theweight detected in the back sensors. Once the person has risen from thechair, of course both the front and the back sensors show a decrease anda steady state with respect to weight. In FIG. 6 it is seen that theperson is risen from the chair at approximately one second. Also it isto be noted that the differential weight shift from the front to theback indicates very little difference between the left to the rightsides. This indicates that the person rose from the chair in asymmetrical manner. This suggests that muscle strength and coordinationis balanced and that the person rose from the chair in a normal balancedfashion relying upon the equal strength and agility with respect tomuscles on both sides of the body.

[0047]FIG. 7 includes graphs quite similar to those set forth in FIG. 6.However, the events required a longer time. Approximately two secondsare required to rise from a chair in the graphs depicted in FIG. 7.Again there is little difference between the left and right sensorsduring the event. Thus, though the person took almost twice as long, theperson arose from the chair in a very symmetrical fashion. Thisindicates the balance of the person is symmetrical although because ofthe prolonged time to rise from the chair there may be an indication ofweakness or diminished strength or some other indicator of aphysiological problems.

[0048]FIG. 8 indicates a person rising slowly from a chair and thenmomentarily falling back into the chair before completely rising. Thefact that the person fell back into the chair is indicated by thebimodal peaks in the graphs. However, in this circumstance thedifference between the left and right sensors is still comparableindicating that the person rose in a symmetric fashion. These charts mayindicate a loss of balance, a diminution or loss of muscle strength orother physiological problems, but in any event, suggest furtherdiagnosis is in order.

[0049]FIG. 9 includes graphs or tracings that indicate that the personfavors or leans to his or her left side. That is, the left sidemeasurements increase while the right side measurements decrease.Otherwise, there is a shift from the back sensors to the front sensorsas the person rises. The time period or term in order for the person toeffect the movement is also somewhat prolonged. The pathophysiologicalindications from these charts suggest a weakness on the right side inmuscle or muscle control or balance. Again, further testing and analysisare indicated.

[0050] Maintaining a record of such charts for a particular patient andcomparing the charts over time will enable a practitioner to understandwhether the person is maintaining a certain level of health, whether thepatient is declining in health and whether, for example, therapy isassisting the patient with respect to recovery. Further charts alongwith norms associated with certain movements will facilitate thepractitioners analysis and diagnosis.

[0051] Finger-Tip/Arm Rest ECG

[0052] Another type of data collected via the chair sensors relates toelectrical sensing, most typically, ECG sensing. Thus, two electrodes34, one mounted on the left arm 30 of the chair and one mounted in theright arm 30 of the chair, may be used to measure tile standard lead oneECG vector. The use of two electrodes 34 without a reference electrodeis made possible by using an analog design incorporating a very highcommon mode rejection. The placement of the electrodes 34 is such thatthe measurement is made by the patient holding his or her arms and handson both of the arms 30 of the chair simultaneously.

[0053] A second use of the two electrodes 34 is to provide a patientactivated switch. Placing the fingers on the electrodes 34 provides onestate of the switch, while removing the fingers from the electrodes 34provides the second state of the switch. For example, the electrodes 34of both arms 30 may require touching or activation to initiate asequence of sensor operation. Consequently, initiation of the record ofan ECG may not begin until the patient properly places fingers from eachhand on separate sensors 34. Also, the patient may be required tooperate the switches 34 in a sequence or in response to an audio orvideo signal to diagnose sight, sound, response time or memory orattention deficit.

[0054] Alternatively, for ECG monitoring, two electrodes 34 are placedon one arm 30 of the chair and a third electrode 34 (as a ground) isplaced on the other arm 30 of the chair. The input from the twoelectrodes 34 on the same arm can then be monitored to provide for thevector one ECG reading or signal.

[0055] Multiple other variations of electrode positioning on the arms 30and/or belts 24, 26, 28 are within the scope of the invention. Forexample, the sensors may be placed in the back support 16 of the chair.Such placement may incorporate redundancy inasmuch as multiple sensorsmay be provided to sense the same feature of patient health. Forexample, positioning of multiple electrodes 34 on each arm forengagement by separate digits of each hand can be utilized incombination with various prescribed video and audio instructions (eitherpreprogrammed or initiated by the central station diagnostician). Thismay enable detection or analysis of muscular control, memory, attentionspan, etc. which, in turn, provide valuable diagnostic information fordetection of disease such as stroke, Alzheimer disease, etc.

[0056] Safety Belt Diagnostic ECG

[0057] The “safety belt” is a diagnostic element which, in a preferredembodiment, consists of two portions, a chest strap 26 which crosses thepatient's chest from the upper right to the lower left, and a lapportion 28 which crosses the patient horizontally above the abdomen fromthe right side to the left side where it meets with the chest strap 26.The straps 28, 26 are made with an elastic material allowing initialplacement of electrode pads 29 to accommodate a patient's anatomy.Electrode pods 29 are thus placed in the standard chest predefinedpositions used for the limb measurements of, LL and RL as well as thestandard chest positions used for C1, C2, C3, C4, C5, and C6 of an ECG.The leads LA and RA are obtained from the finger-tip or arm restelectrodes 34. The elasticity of the belt strap 28 insures good skincontact while the measurement is made. When the measurement is completedthe safety belt strap 28 returns into a housing 31 mounted on the sideof the chair. A full 12 lead ECG consisting of leads 1, 11, 111, AVR,AVL, AVF, V1, V2, V3, V4, V5, V6 is derived from the input electrodes29.

[0058] Alternative placement of electrodes is, as suggested above,possible. Thus, the number of electrodes, their placement, theirstructure and construction are variable depending upon the diagnosticprotocol to be adapted.

[0059] Non-Invasive Blood Pressure

[0060] A cuff 33 is used to measure non-invasive blood pressure and isstored on the side of the chair. Cuff 33 is designed for easy placementon a patient's arm. The blood pressure measurement is activated remotelyafter the patient slides his arm into cuff 33. Electronics in the chaircontrol enclosure or housing 50 automatically monitors inflation anddeflation of the cuff. Sensors in cuff 33 detect pressure and pressurechange. Measurement of blood pressure may be effected separately orsimultaneously with other tests described. Again, a separate datachannel coordinated with other channels may be utilized in the system.Also, the data may be gathered, processed, transmitted and analyzed inthe manner described above for load cell data. Other alternatives fordata storage and coordination with other parameters are possible againdepending upon the diagnostic protocol adopted and typically controlledfrom the central station.

[0061] Saturated Pulse Oximetry

[0062] Pulse oximetry is a means to confirm the amount of oxygen in theblood. Standard instrumentation uses a comparison of absorption of redand infra-red light by the body tissue to determine the percentage ofoxygenated blood cells by placing a finger clip emitter/sensor 40 onpatient's finger. The chair incorporates a finger clip or socket 40located in the arm 30 of the chair. The measurement will be made by thepatient placing his finger in the finger clip or socket 40. A socket 40may be provided in one or both arms 30. Again, the data may be processedas described above.

Blood Glucose Analysis

[0063] Blood glucose measurements are usually made by placing a drop ofblood on a chemically treated paper and recording the color of thepaper. The chair has an optical sensor 38 built into the arm 30 whichcan measure the color of the paper. In addition, a sterilized fingerprick 60 using disposable finger pricks is built into the arm 30. Acontainer 41 on the side of the chair is used to store finger pricks andpaper, while another container 62 is used for disposing the usedmaterial. Alternatively, skin sensors can be attached to the chair tononinvasively measure blood glucose levels. The chair may alsoincorporate newer blood glucose measuring devices that do not requirethe drawing of a blood sample.

[0064] Heart and Lung Sounds

[0065] An electronic stethoscope is incorporated in strap 26 or may beattached to the side or back support 16 of the chair to assess heart andlung sounds. Alternatively, the stereoscope may be incorporated in beltor strap 26.

[0066] Respiratory Flow Measurements

[0067] A respirometer 35 attached to the side of the chair and is usedto measure pulmonary inspiratory and expiratory flow functions.Respirometer 35 may be incorporated in strap 26.

[0068] Skin Resistance

[0069] Skin resistance is measured by placing a high frequency signalinto the finger tip electrode 34 and measuring the associated resistancebetween the electrodes 34.

[0070] Manual Strength Measurement

[0071] Hand grips 36 placed on one or both arms 30 with sensors are usedfor early detection of neurological and neuromuscular dysfunction. Thegrips 36 measure the active force caused by muscular contraction as wellas passive sensing of finger motion associated with tremors. Similartechnology is built into the leg support 18 rest for the determinationof leg muscle force.

[0072] Typically, referring to FIG. 3, one embodiment of a real timehand grip monitoring device comprises a bladder 36 in the form of anellipsoid. However, other bladder shapes may be used which arecomfortable for a patient to hold or grip. The bladder 36 may bepositioned and incorporated in one arm 30 or two bladders 36 may beprovided, one in each arm 30, i.e., for left hand gripping and for righthand gripping. A comparison of signals from both the left and right handarrangement of bladders 36 is considered important when analyzingcertain muscular and neuromuscular characteristics of a patient.

[0073] The bladder 36 is connected by a tube 70 through a check valve 72to a fluid source 74. Typically, the fluid is air, although other fluidsmay be utilized. The bladder 36 further includes an internal pressuresensor 76 with sensing leads 77 connected thereto. The sensing leads 78connect the sensor 76 with a data recorder 78. The data recorder 78 isconnected with a data comparator 80.

[0074] Typically, the bladder 36 is maintained at atmospheric pressure.When there is no manual pressure applied to the bladder 36, then thereis no pressure differential with respect to atmospheric pressure.Squeezing the bladder 36 increases the pressure within the bladder 36.This pressure is sensed by the pressure sensor 76. The pressure sensor76 produces an electrical voltage proportional to the pressure appliedto the sensor which varies in time, depending upon the patient'sstrength and grip. The voltage contains two elements, a direct currentelement and an alternating current element. The direct current elementrepresents the absolute pressure while the alternating current elementrepresents changes in pressure associated with physiological change, forexample, information relating to muscle or hand tremors.

[0075] Thus, the signal from the sensor 76 is divided into two parallelprocessing paths. The first path is for the direct current signal.Typically, the path will have a filter that removes the AC oralternating current portion of the signal. The second path is for thealternating current portion of the signal. This path removes the directcurrent portion. In each instance, after removal of the appropriateportion of the signal, by virtue of an appropriate filter, the signal isamplified. The signals Arill then be converted into a digital format ifdesired and necessary by hardware and software in housing 50. Thedigital signals then may be transferred to a communication system asdescribed above or processed on site and then transmitted.

[0076] In practice, it is desirable to have a bladder, 36 associatedwith both the left hand and right hand of the patient so as to comparedata with respect to both channels for the left hand and right hand sideof the patient. The patient hand strength with respect to each handprovides additional physiological information, for example, associatedwith stroke and stroke patient recovery.

[0077] In any event, the direct current signal typically will increaseto a steady state value upon manual gripping. The steady state valuerepresents maximum hand strength. The length of time at that fixed valuerepresents the time during which the patient can maintain the maximumhand grip force on the bladder. Integration of that fixed valuerepresents the total energy exerted by the patient. The data istypically recorded for future comparison.

[0078] The alternating current signals are converted to an appropriatefrequency where the data frequency and amplitude are recorded.Historical comparisons can then be made for the individual patient or bycomparison to the standard formats or a standard library of information.Over time, the change in the readings on both channels can bedetermined. The differential readings with respect to left and righthand signal processing can also be determined. Thresholds can be set andan alarm can be provided which will indicate the crossing of a signalthreshold. That may be indicative of a possible abnormality of thepatient.

[0079] An alternative embodiment of the hand grip sensor includes a gripmechanism with load cell sensors in place of the bladder constructiondescribed. Other mechanical or electromechanical substitutes may beutilized to provide the AC and DC signals.

[0080] System Operation

[0081] Of course, the chair is capable of interactive use as part of aremote station/central station system as generally described in theaforementioned U.S. Pat. No. 5,544,649. However, the present inventionincorporates not only sensor specific features associated with thechair, but also system features associated with the means and protocolfor collecting, analyzing, transmitting, and processing data. Also, theinterrelationship of the collected data is made possible for diagnosticimplication. That is, conducting and measuring multiple physicalparameters simultaneously at a remote site provides a better diagnosticoverview of a patient and the described system permits such a diagnosticoverview.

[0082] It is possible, however, to vary the function, elements andconstruction of the diagnostic chair and system with the chair. Forexample, the number of load cells 22 and their geometric array may bevaried in order to enhance the data representative of factors such asweight, respiration, rate, balance, etc. Also, the chair or device maybe utilized in a hospital or clinic and is not restricted to remote siteuse.

[0083] In operation, the patient is directed to sit in the chair and tofollow a series of steps in desired and specific sequence orsimultaneously. The directions are provided through the remotemonitoring audio and video transmission from the central station. Asdepicted in FIG. 4, a video screen 51 and camera 53 are utilized incombination with the chair. As each instrument, for example, the straps26, 28 are attached to the patient by the patient, a signal is initiatedand transmitted from the transmitter receiver 42 to the transmissiondevice 44 and then back to the central station. The electronics andlogic systems in the electronics enclosure 50 control all of the initialsensing and set up and the described processing of the various signalsfrom the patient. Thus, data manipulation is accomplished in thesoftware and hardware and maintained in the chair or at the remote siteas an initial first step. The essential data is then transmitted fromthe transmitter receiver to the transmission device and ultimately oversome network such as a switched network to the central station. Uponcompletion of the examination, the patient will rise from the chair anddisconnect the chair from a power source.

[0084] The platform may be in the form of a chair as described on in theform of a bed or gurney or other subject support device. Repositioningthe sensors on various platforms is viewed as within the scope of theability of a practitioner in the relevant field. The platform is alsouseful for detection of physical change, monitoring of subject wellness,emergency diagnosis, general health care management, rehabilitationmonitoring, recovery monitoring, information collection, informationdissemination, and interaction with respect to health and wellness forgeriatrics especially Examples of the utility of the device include thefollowing.

EXAMPLE 1 Congestive Heart Failure (CHF) Patients

[0085] Currently CHF patients present one of the biggest challenges ofmedicine. The New England Journal of Medicine reports that heart failureaffects approximately 6 million Americans and is the leading cause ofhospitalization for adults over the age of 65. Annual expenditures forheart failure related costs are estimated as high as $38 billion,according to research conducted by the Journal of the American Collegeof Cardiologists, of which $23 billion is for hospitalizations.

[0086] Numerous studies suggest that comprehensiveheart-failure-management programs can improve patients' quality of life,reduce hospital readmissions and emergency room visits and save overallcosts of treating this condition. Despite the improved results,physicians are concerned about the low level of compliance. The lack ofcompliance results in inaccurate data received from patients with theconsequence of inappropriate treatment. The present system and devicepermits transmission of data such as weight, ECG, balance andcoordination information etc., from the patient site to the monitoringcenter which will be done automatically without the need of patientactivity, audio-visual verification of medication in-take, and visualcontact with a health practitioner to maintain human contact.

EXAMPLE 2 Diabetes

[0087] Diabetes affects 5.9% of the U.S. population, estimated to be15.7 million Americans. Approximately half of all diabetes occurs inpeople older than 55. Of the 65 and older population yearly 18.4% (6.8million people have diabetes). Diabetes causes many seriouscomplications, including blindness, heart disease and kidney failure.One in four patients with diabetes develops foot problems which requiretreatment. Sixty thousand amputations are performed on people withdiabetes in the U.S. each year. Complications from diabetes costs theU.S. economy $45 billion each year, with an additional $47 billionattributed to indirect costs from diabetes-related disabilities.

[0088] Diabetes requires daily self management. Education, frequentmonitoring and medication adjustments in the home setting with thedisclosed device will help patients achieve better glucose and bloodpressure control, thereby preventing or slowing the progression ofdiabetes complications, provide psychological support achieved byaudio-visual interaction with a nurse, and provide the capability ofmonitoring and retrieving various vital signs (i.e., ECG, NIBP, weight)and clinical observations (i.e., wounds, swelling, etc.) and to preventcomplications such as cardiac problems and circulatory problems leadingto amputation, stroke, etc.

EXAMPLE 3 Parkinson's Disease

[0089] Parkinson's disease is a progressive disorder of the centralnervous system affecting approximately 2 out of 1,000 people, and mostoften develops after age 50. It is one of the most common neurologicaldisorders of the elderly. Treatment begun early in the disorder can slowprogression of the disease.

[0090] The health care provider may be able to diagnose Parkinson'sdisease based on the symptoms and physical examination. However, thesymptoms may be difficult to assess, particularly in the elderly. Someof these symptoms are: muscle rigidity, stiffness, difficult bendingarms and legs, unstable, or slumped-over posture, loss of balance, gaitchanges, shuffling walk slow movements, difficulty beginning to walk,difficulty in initiating any voluntary movement, small steps followed byhe need to run to maintain balance, freezing of movement when themovement is stopped, inability to resume movement, shaking and tremor,changes in facial expression.

[0091] Some of these symptoms are not specific to Parkinson and may beconfused with other disorders that cause similar symptoms. For example,the posture changes may be similar to osteoporosis or other changesassociated with aging. Lack of facial expression may be a sign ofdepression. The tremor may not appear when the person is sitting quietlywith arms in the lap.

[0092] Untreated, the disorder progresses to total disability, oftenaccompanied by general deterioration of all brain functions. It mayresult in an early death if untreated.

[0093] Treated, the disorder impairs people in varying ways. Most peoplerespond (to some extent) to medications. The extent of symptom relief,and how long this control of symptoms lasts, is highly variable. Theside effects of medications may be severe. The device with its responsetime test and the ability to detect and measure tremors will enable theearly detection of the disease as well as the follow up of the efficacyof the medications.

[0094] The type and number of tests which can be implemented utilizingthe chair or an alternative platform may be varied. All of the testsdescribed need not be performed. Various additional tests may beincorporated into the chair using additional types of sensors. Also, thechair (device) may be automatically controlled from a remote (or near)station to automatically perform a series of tests without a nurse orprofessional guiding the subject. The system can therefore be programmedto conduct testing upon initiation by the subject of a predefinedprotocol. The test results will then be transmitted and/or recorded forlater personal review. Thus, the subject matter of the invention is tobe limited only by the following claims and equivalents thereof.

What is claimed is:
 1. A medical examination device comprising, incombination a platform; a support for the platform with at least threeload sensors geometrically distributed under the support; and an elementfor detecting the load on each of the load sensors to provide a set ofdata signals for medical diagnosis.
 2. The device of claim 1 furtherincluding one or more of the following: (a) diagnostic ECG sensor; (b)blood pressure sensor; (c) respiration rate sensor; (d) pulse oximetrysensor; (e) sonic detector; (f) skin resistance detector; (g) manualgrip sensor; (h) fluid flow rate sensor; and (i) glucometer.
 3. Thedevice of claim 1 wherein the device and includes four support membersfor arrayed in a rectangular array beneath a seat having a front edgeand a back edge, said support members aligned generally with the frontedge and the back edge of the seat, and a load sensor located betweeneach support and a support surface.
 4. The device of claim 1 furtherincluding a load sensor signal processor, said processor including abase reference for each of said load sensors, differential amplifiers toamplify the changes in signal of each load sensor, a high pass filter toremove the DC component of each signal, and a low pass filter to removethe AC component of each signal.
 5. The device of claim 1 furtherincluding a sensor element to sense the voltage associated with each ofthe load sensors and a band pass filter to filter out select signals. 6.The device of claim 4 or 5 her including a signal processor forprocessing the voltage signals from the load sensors and measure thedifferential signal between side to side and front to back with time foreach of the sensors.
 7. The device of claim 1 further including: a handgrip monitoring device comprising, in combination; a bladder; a tubeconnected to the bladder; a source of pressurized fluid for the bladderconnected through the tube; a check valve for monitoring the bladder andtube filled with a volume of fluid; a pressure sensor connected to thebladder for measuring the fluid pressure in the bladder and providing afirst signal representative of the absolute pressure in the bladder anda second signal representative of the change in pressure over time inthe bladder; and a recorder for recording the first signal over ameasured increment of time and for recording the second signal over saidmeasured increment of time, said first signal being integrated andrecorded, said second signal being recorded to provide the frequency andamplitude over the increment of time.
 8. The device of claim 8 or 7further including historical recordings of like signals and a comparatorfor comparing the recorded signals with historical readings.
 9. Thedevice of claim 8 wherein the historical readings are derived from thesame patient.
 10. The device of claim 8 wherein the historical readingsare derived from a non-patient source.
 11. The device of claim 8 furtherincluding an alarm for denoting departure from the historicalrecordings.
 12. The device of claim 1, 4, 5, 6, or 7 in combination witha central station, said device maintained at a remote station, saidstations being linked by two-way audio, video and/or data channels. 13.The device of claim 12 in combination with multiple remote stationdevices and a single central station and further including a controlsystem for monitoring each device.
 14. The device of claim 13 whereinthe control system for monitoring each device includes a switch forconnecting the central station to each of said device individually.